HP-29C: 98 Program Steps, So, why not an even 100?

[teenix]

(08-28-2019 01:18 PM)rprosperi Wrote:  That said, I've 2 questions:

A. There seems to be no register 30, so is that some internal register numbering scheme, and

B. How can both a value and program steps be stored in the same register? The 38C with Continuous memory stores both program and register storage even when off.

Sorry, my error, there are 99 program steps. Registers 16 - 29 (14 x 7) + 1

There are 32 registers available. Not all are available as housekeeping requires some RAM storage.

Register 30 holds data for the program pointer and the value E32D85 stored. If this value does not exist in RAM at switch on, Pr Error will appear on the display, memory is cleared and the value is written to RAM 30. If the value is there at switch on then the calculator retains memory.

The calculator stores a pointer where the program memory resides and as the program grows, less general storage memory is made available to the user.

cheers

Tony